Friendship always benefits love sometimes injures. Seneca
Hate is too great a burden to bear. It injures the hater more than it injures the hated. Coretta Scott King
The unjustifiable severity of a parent is loaded with this aggravation, that those whom he injures are always in his sight. Joseph Addison
The rotten apple injures its neighbour. Italian Proverb
He who injures with the sword will be finished by the sword. Corsican Proverb
A rotten apple injures its companions. English Proverb